This invention relates to the field of flasks useful for various types of culture such as micro-organisms, tissues and the like where a means of steril access through the tope side is desirable.
Historically a variety of assemblies have been used for various forms of culture such as tissue, micro-organisms, and the like. Petri dishes have been used for a long time as have culture tubes. In recent years, culture flasks, particularly the type shown in U.S. Pat. No. 3,449,210 to Rohde, have come into wide spread use. These flasks have proven quite useful particularly if diphase mediums are employed. However a problem develops when it is time to remove material such as individual clones, colonies of cells, or organisms which have developed or been in the flask from the flask. At the present time, the types of material used for these flasks are frequently plactics such as polymehtylmethacrylate and polystrene and the top wall of the flas is removed by use of an electric iron. There are two undesirable results which can occur from this procedure. First, the heat form the iron necessary to melt the plastic, although quit localized, does have an effect on the culture. Secondly, the fumes emitted by the melting operation also can effect the culture.